The present invention relates to a hot stamping cylinder of metal, with a heating system located in the cylinder hollow space. Until now, punching or stamping cylinders for hot stamping processes have been heated by oil in that the inner space of the cylinder has been filled with oil and coupled to an oil circuit with an external oil heating apparatus.
This method is cumbersome and the mobility inside of a printing machine is considerably limited. Additionally, the controlling of the temperature is very sluggish, high energy losses are encountered and problems regarding the disposal of waste oil are produced.
A different method for the heating of the cylinders is based on the application of an electrical heating cartridge in the center of the cylinder with an energy supply through slip rings.
The drawbacks of this solution are the short useful lifetime of the heating wires due to their high temperature stress, a sluggish regulating and long cooling times due to a high heat capacity.